❔ User-defined implicit type conversion + type pattern match

Hello, if I have some type

Either<T1, T2>

Either<T1, T2>

that has a left and right variant, is there a way to get C# to use an implicit converter so that I can write:

foobar is T1 value

foobar is T1 value

❔ User-defined implicit type conversion + type pattern match - C#